scholarly journals Polylactic Acid/Polycaprolactone Blends: On the Path to Circular Economy, Substituting Single-Use Commodity Plastic Products

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2655 ◽  
Author(s):  
Marc Delgado-Aguilar ◽  
Rita Puig ◽  
Ilija Sazdovski ◽  
Pere Fullana-i-Palmer

Circular economy comes to break the linear resource to waste economy, by introducing different strategies, two of them being: using material from renewable sources and producing biodegradable products. The present work aims at developing polylactic acid (PLA), typically made from fermented plant starch, and polycaprolactone (PCL) blends, a biodegradable polyester, to study their potential to be used as substitutes of oil-based commodity plastics. For this, PLA/PCL blends were compounded in a batch and lab scale internal mixer and processed by means of injection molding. Tensile and impact characteristics were determined and compared to different thermoplastic materials, such as polypropylene, high density polyethylene, polystyrene, and others. It has been found that the incorporation of PCL into a PLA matrix can lead to materials in the range of 18.25 to 63.13 megapascals of tensile strength, 0.56 to 3.82 gigapascals of Young’s modulus, 12.65 to 3.27 percent of strain at maximum strength, and 35 to 2 kJ/m2 of notched impact strength. The evolution of the tensile strength fitted the Voigt and Reuss model, while Young’s modulus was successfully described by the rule of mixtures. Toughness of PLA was significantly improved with the incorporation of PCL, significantly increasing the energy required to fracture the specimens. Blends containing more than 20 wt% of PCL did not break when unnotched specimens were tested. Overall, it was found that the obtained PLA/PCL blends can constitute a strong and environmentally friendly alternative to oil-based commodity materials.

Author(s):  
M. S. Rasidi ◽  
L. C. Cheah ◽  
A. M. Nasib

Polylactic acid is a biodegradable polymer derived from renewable resources, showing potentials in replacing traditional petroleum-based polymers, yet its brittleness limits its applications. Thus, blending polylactic acid with acrylonitrile butadiene styrene as well as incorporation of fillers were used to enhance the mechanical and biodegradability properties of polylactic acid by extrusion compounding. The aims of this study to produce and investigate PLA/ABS blend incorporated with natural filler, NFH and IC to improve the properties pf PLA/ABS blends. Two types of fillers used were Nypa fruticans husk and isolated cellulose from Nypa fruticans husk which was obtained by using Soxhlet extraction. Transform Infrared spectroscopy analysis was used to characterize and verified the extracted substance was isolate cellulose. Tensile, impact and biodegradation test were conducted to investigate the mechanical and biodegradability properties. The optimum blend ratio for polylactic acid/acrylonitrile was 75/25 php base on previous studies, and it was found that the incorporation of both fillers, Nypa fruticans husk and isolated cellulose from Nypa fruticans husk had decreased the tensile strength, elongation at break and impact strength of the composite however increased the Young’s Modulus and biodegradation weight loss. Meanwhile, at similar filler content, the tensile strength, Young’s modulus and biodegradation weight loss of polylactic acid/acrylonitrile butadiene styrene blend incorporated with isolated cellulose were higher value compared to polylactic acid/acrylonitrile butadiene styrene blend incorporated Nypa fruticans husk. Furthermore, morphological studies showed a well-coated filler by matrix and reduction of filler pull out when isolated cellulose was incorporated in polylactic acid/acrylonitrile butadiene styrene blend. Therefore, it was found that the incorporation of isolated cellulose in polylactic acid/acrylonitrile butadiene styrene blend, shows higher mechanical and biodegradation properties than polylactic acid/acrylonitrile butadiene styrene blend incorporated with Nypa fruticans husk.


2015 ◽  
Vol 754-755 ◽  
pp. 54-58 ◽  
Author(s):  
M. Syahmie Rasidi ◽  
H. Salmah ◽  
Pei Leng Teh ◽  
Hanafi Ismail

The main purpose of incorporating Nypa Fruticans (NF) into Polylactic Acid (PLA)/Recycled Low Density Polyethylene (rLDPE) biocomposites is to decrease costs and change the properties. Polyethylene–co–acrylic acid (PEAA) was used as a compatibilizer. The effect of NF content and PEAA on the mechanical properties and morphology of the biocomposites were investigated. Results show that the effect of NF content increased Young’s modulus but decreased the tensile strength and elngation at break of PLA/rLDPE/NF biocomposites. It was found that incorporation of compatibilizer (PEAA) increased the tensile strength and Young’s modulus but decreased the elongation at break of compatibilized biocomposites. Scanning electron microscopy (SEM) study of the tensile fracture surface of the biocomposites indicated that the presence of PEAA improved the interfacial interaction between Nypa Fruticans and LDPE matrix.


2010 ◽  
Vol 123-125 ◽  
pp. 193-196 ◽  
Author(s):  
Arpaporn Teamsinsungvon ◽  
Yupaporn Ruksakulpiwat ◽  
Kasama Jarukumjorn

Poly (lactic acid) (PLA), a biodegradable polyester, derived from renewable resources has been widely used in biomedical and packaging applications. However, the shortcomings for using PLA including its processing instability, low melt viscosity and low flexibility limited its applications. To overcome these shortcomings, poly (butylene adipate-co-terephthalate) (PBAT) was blended with PLA to improve ductility of PLA. However, PLA and PBAT are incompatible. Maleic anhydride grafted PLA (PLA-g-MA) was used to enhance the compatibility of the blends. Moreover, the blend of PLA and PBAT exhibited higher elongation at break but lower tensile strength and Young’s modulus than the pure PLA due to the addition of a ductile phase. Therefore, the addition of calcium carbonate (CaCO3) to PLA/PBAT blends led to achieve balanced properties of the blends. In this study, PLA/PBAT blends and PLA/PBAT/CaCO3 composites were prepared by an internal mixer. PLA-g-MA was as a compatibilizer. Mechanical properties and rheological properties of the blend and composites were investigated. In addition, morphologies of PLA/PBAT blend and their composites were observed by a scanning electron microscope (SEM). The incorporation of PBAT gave rise to remarkable improvement in elongation at break and impact strength of PLA. Tensile strength of PLA/PBAT blend was enhanced by adding PLA-g-MA. With increasing CaCO3 content, Young’s modulus of the composites increased while tensile strength and elongation at break decreased.


2014 ◽  
Vol 1052 ◽  
pp. 220-225 ◽  
Author(s):  
Sirirat Wacharawichanant ◽  
Parida Amorncharoen ◽  
Ratiwan Wannasirichoke

The effects of styrene-co-maleic anhydride (SMA) compatibilizer on the mechanical thermal and morphological properties of polyoxymethylene (POM)/acrylonitrile-butadiene-styrene (ABS) blends were inverstigated. POM/ABS blends without and with SMA compatibilizer were prepared by an internal mixer and molded by compression molding. It was found that the dispersion of ABS phase and compatibility could not improve by using SMA compatibilizer in POM/ABS blends due to SMA can be miscible with ABS phase more than POM phase. The addition of ABS in a range of 10-30 wt% could improve the Young’s modulus of POM. Impact strength, tensile strength and percent strain at break of POM/ABS blends decreased with increasing ABS content. The addition of compatibilizer improved Young’s modulus of POM/ABS (60/40, 50/50) blends. The addition of ABS increased the degradation temperature of POM, while SMA compatibilizer did not improve the degradation of POM/ABS blends.


2011 ◽  
Vol 695 ◽  
pp. 170-173 ◽  
Author(s):  
Voravadee Suchaiya ◽  
Duangdao Aht-Ong

This work focused on the preparation of the biocomposite films of polylactic acid (PLA) reinforced with microcrystalline cellulose (MCC) prepared from agricultural waste, banana stem fiber, and commercial microcrystalline cellulose, Avicel PH 101. Banana stem microcrystalline cellulose (BS MCC) was prepared by three steps, delignification, bleaching, and acid hydrolysis. PLA and two types of MCC were processed using twin screw extruder and fabricated into film by a compression molding. The mechanical and crystalline behaviors of the biocomopsite films were investigated as a function of type and amount of MCC. The tensile strength and Young’s modulus of PLA composites were increased when concentration of MCC increased. Particularly, banana stem (BS MCC) can enhance tensile strength and Young’s modulus of PLA composites than the commercial MCC (Avicel PH 101) because BS MCC had better dispersion in PLA matrix than Avicel PH 101. This result was confirmed by SEM image of fractured surface of PLA composites. In addition, XRD patterns of BS MCC/PLA composites exhibited higher crystalline peak than that of Avicel PH 101/PLA composites


2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.


2021 ◽  
Author(s):  
MICHAEL N. OLAYA ◽  
SAGAR PATIL ◽  
GREGORY M. ODEGARD ◽  
MARIANNA MAIARÙ

A novel approach for characterization of thermosetting epoxy resins as a function of the degree of cure is presented. Density, cure kinetics, tensile strength, and Young’s modulus are experimentally characterized across four mixing ratios of DGEBF/DETDA epoxy. Dynamic differential scanning calorimetry (DSC) is used to characterize parameters for a Prout-Thompkins kinetic model unique to each mixing ratio case through a data fitting procedure. Tensile strength and Young’s modulus are then characterized using stress-strain data extracted from quasi-static, uniaxial tension tests at room temperature. Strains are measured with the 2-D digital image correlation (DIC) optical strain measurement technique. Strength tends to increase as amine content use in the formulation increases. The converse trend is observed for Young’s modulus. Density measurements also reveal an inverse relationship with amine content.


2018 ◽  
Vol 33 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Kuhananthan Nanthakumar ◽  
Chan Ming Yeng ◽  
Koay Seong Chun

This research covers the preparation of poly(lactic acid) (PLA)/sugarcane leaves fibre (SLF) biofilms via a solvent-casting method. The results showed that the tensile strength and Young’s modulus of PLA/SLF biofilms increased with the increasing of SLF content. Nevertheless, the elongation at break showed an opposite trend as compared to tensile strength and Young’s modulus of biofilms. Moreover, water absorption properties of PLA/SLF biofilms increased with the increasing of SLF content. In contrast, the tensile strength and Young’s modulus of biofilms were enhanced after bleaching treatment with hydrogen peroxide on SLF, but the elongation at break and water absorption properties of bleached biofilms were reduced due to the improvement of filler–matrix adhesion in biofilms. The tensile and water properties were further discussed using B-factor and Fick’s law, respectively. Furthermore, the functional groups of unbleached and bleached SLF were characterized by Fourier transform infrared analysis.


2018 ◽  
Vol 29 (1) ◽  
pp. 48-53
Author(s):  
Manuela Gonçalves de Souza e Silva ◽  
Eliseu Aldrighi Münchow ◽  
Rafael Pino Vitti ◽  
Mário Alexandre Coelho Sinhoreti ◽  
Evandro Piva ◽  
...  

Abstract The aim of this study was to synthesize and evaluate physicochemical properties of a new salicylate derivative in experimental calcium-based root canal sealers. Two salicylate derivatives were synthesized for the transesterification reaction of methyl salicylate with two different alcohols (1,3-butylenoglicol disalicylate-BD and pentaerythritol tetrasalicylate -PT) in molar ratio 1:3 and 1:6, respectively. The products (BD and PT), were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance spectroscopy (RMN). Calcium-based experimental sealers were prepared with the same catalyst paste (60% of MTA, 39% of n-ethyl-o-toluenesulfonamide, and 1% titanium dioxide) and four different concentrations of BD and PT in the base pastes (40/0 - control, 35/5, 30/10 and 20/20) with 60% of bismuth oxide. The experimental sealers were evaluated for setting time, solubility (24 h, 7, 14 and 30 days), diametral tensile strength and Young’s Modulus. Data were analyzed by one- or two-way ANOVA with Tukey’s test (p<0.05). The addition of PT reduced the materials setting time. After 24 h the sealer 40/0 and 35/5 had higher solubility, and after 14 and 28 days the sealer 20/20 showed the lowest solubility (p<0.05). After 7 days the sealer 20/20 stabilized its solubility. The sealer 40/0 presented the highest values and the 20/20 presented the lowest values of diametral tensile strength and Young’s modulus (p<0.05). The addition of PT to calcium-based root canal sealers provides benefits to the setting time and solubility.


2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878528 ◽  
Author(s):  
Zirong Luo ◽  
Xin Li ◽  
Jianzhong Shang ◽  
Hong Zhu ◽  
Delei Fang

A modified rule of mixtures is required to account for the experimentally observed nonlinear variation of tensile strength. A modified Halpin–Tsai model was presented to predict the Young’s modulus of multiscale reinforced composites with both micron-sized and nano-sized reinforcements. In the composites, both micron-sized fillers—carbon fibers—and nano-sized fillers—rubber nanoparticles and carbon nanotubes—are added into the epoxy resin matrix. Carbon fibers can help epoxy resins increase both the tensile strength and Young’s modulus, while rubber nanoparticles and carbon nanotubes can improve the toughness without sacrificing other properties. Mechanical experiments and scanning electron microscopy observations were used to study the effects of the micron-sized and nano-sized reinforcements and their combination on tensile and toughness properties of the composites. The results showed that the combined use of multiscale reinforcements had synergetic effects on both the strength and the toughness of the composites.


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